München, Techn. University, Diss., 2005.

Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.

Thesis (M.S.)--South Dakota State University, 2005. / Includes bibliographical references (leaves 42-49). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (M.S.)--South Dakota State University, 2005. / Includes bibliographical references (leaves 42-49).

No description available.

As cartilage tissue has limited repair capacities, tissue engineering has emerged as a promising alternative for cartilage repair. The scaffold is a primary component of the tissue engineering design, yet little information exists regarding the effects of polymer and scaffold properties on tissue growth. In this study, we have developed a novel scaffold, PLG microspheres, for use in cartilage tissue engineering, which has the capacity for alterations in polymer and scaffold. We examined the effects of molecular weight, hydrophobic capping, delivery of Mg(OH)2, microsphere size, and controlled release of IGF-I. Our findings demonstrated that polymer parameters distinctively affect tissue and matrix output. Specifically, micro spheres with high molecular weight polymer produced tissue with high GAG content and tissue mass in vivo and in vitro, while micro spheres with capped polymer induced steady tissue and matrix accumulation, but may have precluded cell attachment. Release of buffer to the growing cartilage had negative effects on tissue formation in vivo and in vitro. Additionally, increasing microsphere diameter generated more samples with center of necrotic tissue. The presence of microspheres induced greater cartilage mass and matrix content than cartilage from cells alone. Delivery of IGF-I induced a dose-dependent effect on matrix and tissue production in vivo, with the highest effective load of IGF-I (0.3%) generating the most matrix and tissue accumulation. In contrast, the in vitro IGF-I dose-dependent effect induced on matrix and tissue production peaked at a dose of 0.02% IGF-I, with higher doses generating less tissue and matrix. Taken together, changes in polymer or scaffold composition and release of growth factor can be optimized to form cartilage with enhanced tissue parameters. Moreover, these results demonstrate a novel scaffold with potential to support cartilage regeneration and provide simultaneous drug delivery.

Abstract The aim of the present study was to evaluate whether bacterial vaginosis (BV) diagnosed in early pregnancy and treated with vaginal clindamycin affects pregnancy outcome, and to investigate the predictive value of interleukins-6 (IL-6) and -8 (IL-8), and insulin-like growth factor-binding protein-1 (IGFBP-1) in cervical secretions, separately and combined by cervical measurement with transvaginal ultrasonography, on preterm delivery. A further aim was to analyze retrospectively the significance of absent or reversed end-diastolic velocity (AREDV) in the umbilical artery on perinatal outcome, and to investigate the short- and long-term outcome of infants born prematurely as a result of various causes (indicated preterm birth, preterm premature rupture of the membranes=PPROM). Bacterial vaginosis (BV) was screened in 1956 women in a low-risk population at the first antenatal visit, using Gram stain. One hundred and one of 143 BV-positive women were randomized to receive vaginal clindamycin or placebo. Seventy-seven women at 22-32 gestational weeks with premature uterine contractions, and 78 controls were recruited for assay of cervical IL-6, IL-8-, and IGFBP-1, and ultrasonographic measurements, which were repeated twice at two-week intervals. Eighty-three women with AREDV in the umbilical artery in high-risk pregnancies at less than 34 gestational weeks (e.g. pre-eclampsia, small-for-gestational age [SGA]) between the years 1988-95 were analyzed retrospectively as regards perinatal outcome. Further, for 103 women between the 24th and the 33rd week of pregnancy, delivered by cesarean section because of maternal or fetal indications, and for 103 matched women, between the years 1990-97, their infants were analyzed as regards neonatal mortality and morbidity, and the outcome at one year of corrected age. Similarly, 78 women with PPROM at gestational weeks 17-30, and 78 controls were also analyzed. The prevalence of BV was 7.3% (143/1956) and the preterm birth rate in women with BV was 9.9%. Preterm birth occurred in 21% vs. 0% according to whether or not BV persisted. The preterm birth rate was 14% in the clindamycin group vs. 6% in the placebo group. Cervical IL-6 at a concentration of 128 ng/L had a 73% sensitivity and 77% specificity in predicting preterm birth (35% vs. 6%). The combination of IL-6 and a cervical index of > 0.2 increased the specificity to 97%, the sensitivity falling to 45%. Concentrations of IGFBP-1 were most elevated (> 21 μg/mL) in cases with neonatal infections (36% vs. 2%). In cases of absent end-diastolic velocity (AEDV) the perinatal mortality (PNM) rate was 9%, compared with 36% in the reversed end-diastolic velocity (REDV) group. Respiratory distress (RDS) and hypoglycemia, and chronic lung disease (CLD; 15% vs. 3%) occurred significantly more often in the indicated than in the spontaneously preterm infants. The PPROM infants had more limb contractures (8% vs. 0%) and pulmonary hypoplasia (12% vs. 5%) and more chronic lung problems up to one year of age than the spontaneously preterm born infants without PPROM. The persistence of pregnancy BV is a risk factor for preterm birth, but vaginal clindamycin used in a low-risk population in early pregnancy is of no use in reducing the preterm birth rate in cases of BV. The level of IL-6 has a relatively low sensitivity and a limited role as a single method in clinical decision making but in combination with cervical examination by ultrasonography it seems to have a predictive role in cases of threatened preterm birth. A finding of AREDV in the umbilical artery is a warning signal of threatened fetal asphyxia. Infants born after indicated preterm delivery (for fetal or maternal reasons) or PPROM are at risk of later chronic lung disease.

We have previously shown that the insulin-like growth factor 1 receptor (IGF-1R) translocates to the cell nucleus, where it binds to enhancer-like regions and increases gene transcription. Further studies have demonstrated that nuclear IGF-1R (nIGF-1R) physically and functionally interacts with some nuclear proteins, i.e. the lymphoid enhancer-binding factor 1 (Lef1), histone H3, and Brahma-related gene-1 proteins. In this study, we identified the proliferating cell nuclear antigen (PCNA) as a nIGF-1R-binding partner. PCNA is a pivotal component of the replication fork machinery and a main regulator of the DNA damage tolerance (DDT) pathway. We found that IGF-1R interacts with and phosphorylates PCNA in human embryonic stem cells and other cell lines. In vitro MS analysis of PCNA co-incubated with the IGF-1R kinase indicated tyrosine residues 60, 133, and 250 in PCNA as IGF-1R targets, and PCNA phosphorylation was followed by mono- and polyubiquitination. Co-immunoprecipitation experiments suggested that these ubiquitination events may be mediated by DDT-dependent E2/E3 ligases (e.g. RAD18 and SHPRH/HLTF). Absence of IGF-1R or mutation of Tyr-60, Tyr-133, or Tyr-250 in PCNA abrogated its ubiquitination. Unlike in cells expressing IGF-1R, externally induced DNA damage in IGF-1R-negative cells caused G(1) cell cycle arrest and S phase fork stalling. Taken together, our results suggest a role of IGF-1R in DDT.

In the present study, two insulin-like growth factor-binding protein 7 (IGFBP7) C-terminal-peptides were expressed as fusion proteins to bacterial verotoxin pentamerization domain as shown by Western blotting, ELISA and mass spectroscopy. Both in vivo-biotinylated recombinant products were purified from bacterial lysates by IMAC and used directly for panning along with the recombinant IGFBP7 protein using the LAC-M Camelidae naïve single domain antibody (sdAb) library. Target-specific sdAbs to both parental protein and peptide fusions were identified by phage ELISA. Twelve different clones were isolated by phage-ELISA screening and their sdAb genes were sequenced. Soluble sdAbs and their pentameric formats were expressed in TG1 E. coli, purified by IMAC and characterized by ELISA and SPR. Several sdAbs are currently under study, however anti-IGFBP7 (P12/M12) was extensively characterized and exhibited promising anti-tumorigenic effect on PANC-1 cell lines by blocking IGFBP7 promoting activity. This study provides the basis for developing a novel imaging/therapeutic reagent for targeting and treating brain tumor angiogenesis in early stages of tumorogenesis and can also be used as a molecular tool to monitor the degree of angiogenesis in gliomas which may help to improve the clinical management of brain tumors.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22640号 / 医博第4623号 / 新制||医||1044(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 近藤 玄, 教授 斎藤 通紀, 教授 篠原 隆司 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM